Hierarchical and fault-tolerant data aggregation in wireless sensor networks

This paper presents three hierarchical algorithms for data aggregation in wireless sensor networks where sensors can crash and recover. The network is divided in several regions. The algorithms ensure (i) the selection of a common data aggregator sensor within each region, in charge of the collection of local data, and (ii) the selection of a unique super-aggregator sensor, in charge of the collection of global data, among all the aggregators. Both selections are achieved by implementing the Omega failure detector, which provides a self-organizing and fault-tolerant leader election service. We also introduce a battery depletion threshold to provide wireless sensor network QoS